Oil burner nozzle swirler assembly



June 28, 1966 KEYES ETAL 3,258,057

OIL BURNER NOZZLE SWIRLER ASSEMBLY Filed July 31, 1964 I2 FIG] Q 19. W23 25 58 I .v as m 41 mm A 59 r 2 l 39 1 11 14 E) 2734 4 5. (.//slm= vgvfig 49 26 36 24 INVENTORS JACK KEYES ERWIN LOUIS OEHLERKING ATTORNEYUnited States Patent 3,258,057 OlllL BURNER NOZZLE SWIRLER ASSEMBLY JackKeyes, Glencoe, and Erwin Louis Oehlerking, Des Plaines, lllL, assiguorsto International Telephone and Telegraph Corporation, New York, N.Y., acorporation of Maryland Filed July 31, 1964, Ser. No. 386,517 4 Claims.(Cl. 15876) This invention relates generally to oil burners of the guntype, and particularly to an improved swirler for the combustion air ofsuch burners.

One of the principal objects of the invention is to provide an airswirler structure for use with a gun type oil burner so as to giveimproved combustion to the oil-air burning mixture.

Another object is to provide an improved swirler structure which willsupply combustion air in sufficient quantity at the burner nozzle togive initial combustion thereat, and additional air at points spacedfrom the burner nozzle to complete the combustion.

Still another object is to provide a swirler structure which will supplya quantity of air at the burner nozzle for flame propagation immediatelyadjacent to the nozzle, and for completion of the combustion at pointsspaced closely to the nozzle.

Yet another object is to provide a swirler structure which will supply asufficient quantity of air to give good preliminary burning at thenozzle, so that there is no dancing of the flame toward and away fromthe nozzle, and to the end that there is no pulsation of the flamelongitudinally of the axis of the burner gun.

A further object is to provide a swirler structure characterized byswirler blades which each of which has an outer portion of rather largepitch for causing the combustion air to cut across the marginal portionsof the flame pattern to give an air envelope completing the combustionof the oil-air burning mixture, and an inner smaller portion of lesserpitch to divert a portion of the combustion air directly to the burnernozzle to initiate the burning of an oil-air mixture thereat and causethe flame to propagate within the air envelope provided by the outerportions of large pitch.

A still further object is to provide a swirler structure constructedaccording to the foregoing object in which a shorter flame path willresult in a more compact and stable flame, the holding back of the flamepath, and the ready accommodation to any gun type oil burner.

Another and final object is to provide a swirler assembly characterizedby a central cone placed in close proximity to the burner nozzle butspaced therefrom, and adapted by the air moving therepast to pick updroplets of oil from the burner nozzle tip and divert them into an airblast from the swirler blades, the central cone supporting the swirlerblades having outer portions of large pitch for causing the combustionair to cut across the marginal portions of the flame pattern to give anair enve lope completing the combustion of the oil-air burning mixture,and inner smaller portions of small pitch to divert a portion of thecombustion air directly to the burner nozzle to initiate with the airmoving through the central cone and past the nozzle tip the burning ofthe oil-air mixture at the burner nozzle tip, and to cause the flame topropagate within the air envelope provided by the blade portions oflarge pitch.

Other objects and important features of the invention will be apparentfrom a study of the specification following taken with the drawing whichtogether describe and illustrate a preferred embodiment of theinvention, and what is now considered to be the best mode of practicingthe principles thereof. Other embodiments may be suggcsted to thosehaving the benefit of the teachings herein,

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and such other embodiments are intended to be reserved especially asthey fall within the scope and purview of the subjoined claims.

In the drawing:

FIG. 1 is a longitudinal sectional view through an oil.

burner tube showing the improved oil burner nozzle swirler assemblyaccording to the present invention mounted therein;

FIG. 2 is a rear elevational view of the oil burner nozzle swirlerassembly;

FIG. 3 is a side elevation view thereof; and

FIG. 4 is a longitudinal sectional view taken through the improvedswirler and the discharge nozzle upon which it is mounted.

Referring now to the drawing, the improved oil burner nozzle swirlerassembly is referred to generally by the reference numeral 10 and isshown in situ with respect to a burner tube 11, the forward end of whichextends for a short distance, approximately A", through an opening 15 inand beyond a wall 12 defining a combustion space 13 of a heater, notshown. A flange 14 encircling the tube 11 properly limits the positionof burner tube 11 within combustion space 13.

The burner tube 11 has supported therewithin a supply pipe 17 connectedat its rear end to a pipe 18 by an elbow 19 and a coupling 19a thereat.Fuel oil is supplied by a pipe 17 to a burner nozzle indicated generallyby reference numeral 20. It comprises a hollow body member 21 which isexternally threaded at 22 for coupling to the supply pipe 17 at acoupling 23, there being a nut 25 formed on body member 21 for suchattachment.

The hollow body member 21 of burner nozzle 20, see FIG. 4, has a forwardtip 24 formed with an axial discharge passage 26. An inner core 27 isprovided within hollow body member 21 at the discharge passage 26, andis held in place by a hollow set screw 28 threaded at 29 to the bodymember 21. Core 27 and set screw 28 have aligned axial passages 31 sothat oil fed by supply pipe 17 enters these passages and is dischargedradially from core 27 by passages 32 into a pressure space 33surrounding core 27. Core 27 has a spherical face 34 in seatingrelationship with the inner face of tip 24. The oil can reach dischargepassage 26 only by way of slots 36 formed on the spherical face 34. Asintered filter element 35 is threaded into the hollow body member 21 tofilter out any impurities in the oil being fed to the tip 24.

The burner nozzle 20 cooperates with ignition structure 39 secured by aclamp 38 to the supply pipe 17. An electrode 39 terminating in a tip 41spaced a short distance from burner nozzle is made as part of theignition structure 37.

The burner nozzle 20 is adapted to support the swirler 10 which has asupport spider 42 having radial arms 44 extending from a central hub 46having a flange 47 press fitted to the body member 21 against the nut 25thereon. The radial arms 44 have forward extending portions 43 welded attheir forward ends to an air directing central frusto cone-shapedcentral supporting member 48 having a forward opening 49 in proximity tothe tip 26.

The central supporting member 48 is part of a larger assembly formingthe swirler 10, and is preferably formed integrally with a plurality offan-like blades 51 which may be considered generally radial extensionsof the coneshaped member 48. The entire assembly comprising fanlikeblades 51 and frustro-cone-shaped member 48 may be formed from sheetmetal by stamping and forming operations in which the blades 51 aredefined by cutting radial slits 52 which at their inner ends havecircumferentially extending slits 53 formed at a uniform distance fromthe center of frusto-cone member 48.

After the forming of slits 52 and 53 the metal of each blade 51 is bentto give an outer blade portion 54 of large 11 to cut across the marginalportions of a flame pattern resulting from the ignited and atomized fuelat the burner nozzle tip 20. I

Each of blades 51 has small portions 56 at the inner free ends thereof-with considerably smaller pitch than the outer blade portions 54 todivert a portion of the combustion air moving in theburner tube 11directly to the oil discharge nozzle to initiate the burning of anoil-air burning mixture and the propagation thereof within the airenvelope provided by the blade portions 54 of larger pitch. I

-The outer marginal portions of the blade portions 54 may be flattenedas at 57, all to lie in a common plane to be welded or brazed to anannular connecting band 58 which preferably bears against a lip flange59 formed at the front end of the burner tube 11.

The described fan blades of large pitch and the inner smaller portionsthereof of smaller pitch have been found to give a flame pattern to theburning oil-air mixture of properties which are eminently desirable, ascontrasted to the flame patterns obtained with structure of the priorart. It appears that the smaller portions of small pitch providessufficient air at the nozzle tip greatly to implement the burning, sothat the burning may be confined close thereto without the dancing ofthe flame toward and away from the burner tip. The larger blade portionsof greater pitch appear to provide large volumes of air cutting acrossthe marginal portions of the burning oil-air mixture to give an airenvelope completing the combustion and without the dancing of theburning mixture therewithin.

With the elimination of the dancing effect it has been found that anynoise of operation is greatly minimized which is always a greatly soughtafter advantage.

Having thus described this invention in such full, clear, concise andexact terms as to enable any persons skilled in the art to which itpertains to make and use the same, and having set forth the best modecontemplated of carrying out this invention, the subject matter regardedas being patentable is particularly pointed out and distinctly claimedin what is claimed, it being understood that equivalents ormodifications of, or substitutions for, parts of the above specificallydescribed embodiment may be made without departing from the scope of theinvention as set forth in what is claimed.

We claim:

1. A swirler for use with an oil burner of the gun type wherein airflows forwardly in a burner tube to a combustion cahmber and past aliquid atomization oil discharge nozzle, said swirler being adapted tobe supported transversely in said burner tube adjacent said dischargenozzle and comprising a plurality of segmental symmetrically arrangedfan-like blades each having an outer portion of large pitch for causingcombustion air to cut across the marginal portions of a flame patternresulting from ignited and atomized fuel to give an air envelopecompleting combustion of an oil-air burning mixture, and each having aninner smaller portion of lesser pitch to divert a portion of thecombustion air directly to the oil discharge nozzle to initiate theburning of an oil-air mixture thereat and cause the oil-air burningmixture to propagate within the air envelope provided by the portions oflarge pitch.

2. The invention according to claim 1 wherein said fanlike blades aresecured at their outer extremities to an annular rim having an outerdiameter corresponding to the inner diameter of said burner tube.

3. The invention according to claim 1 wherein the means for supportingsaid central annular supporting member includes an inner ring head bysaid burner nozzle and a plurality of radially spaced members secured tosaid inner ring at their inner ends and at their outer ends to saidannular supporting member.

4. The invention according to claim 1 wherein said annular supportingmember has an inner forward portion formed as a truncated cone in aposition to intercept a portion of the air within said burner tube anddirect same against said oil discharged nozzle.

References Cited by the Examiner UNITED STATES PATENTS 1,494,013 5/1924Peabody 1581.5

1,793,111 2/1931 McDonald 1581.5

2,976,919 3/1961 SanBorn 158-76 2,976,920 3/1961 SanBorn 158-76FREDERICK L. MATTESON, JR., Primary Examiner.

'- R. A. DUA, Assistant Examiner.

1. A SWIRLER FOR USE WITH AN OIL BURNER OF THE GUN TYPE WHEREIN AIRFLOWS FORWARDLY IN A BURNER TUBE TO A COMBUSTION CHAMBER AND PAST ALIQUID ATOMIZATION OIL DISCHARGE NOZZLE, SAID SWIRLER BEING ADAPTED TOBE SUPPORTED TRANSVERSELY IN SAID BURNER TUBE ADJACENT SAID DISCHARGENOZZLE AND COMPRISING A PLURALITY OF SEGMENTAL SYMMETRICALLY ARRANGEDFAN-LIKE BLADES EACH HAVING AN OUTER PORTION OF LARGE PITCH FOR CAUSINGCOMBUSTION AIR TO CUT ACROSS THE MARGINAL PORTIONS OF A FLAME PATTERNRESULTING FROM IGNITED AND ATOMIZED FUEL TO GIVE AN AIR ENVELOPECOMPLETING COMBUSTION OF AN OIL-AUR BURNING MIXTURE, AND EACH HAVING ANINNER SMALLER PORTION OF LESSER PITCH TO DIVERT A PORTION OF THECOMBUSTION AIR DIRECTLY TO THE OIL DISCHARGE NOZZLE TO INITIATE THEBURNING OF AN OIL-AIR MIXTURE THEREAT AND CAUSE THE OIL-AIR BURNINGMIXTURE TO PROPAGATE WITHIN THE AIR ENVELOPE PROVIDED BY THE PORTIONS OFLARGE PITCH.